This program consists of four projects. Project I will study the effects of single injections of colchicine on mouse reproduction specifically effects on the placenta, the umbilical cord and embryo. Project II is to study the ability of species of Oxytricha to resist anoxia. Project III will be a study of the mutagenicity of environmental pollutants for the mold Sardaria brevicollis, mutagenicity being considered an evidence of a harmful effect. Project IV is a study of trace metal and biological pollutants in natural waters. Emphasis is placed on the development of special measurement and instrumental techniques.